Portable boat skidway

ABSTRACT

A portable boat skidway is provided by combining lengths of steel rods interconnected by flexible joints in a ladder-like array with skidding tubes of high density polymeric material which serve as &#34;rungs&#34;. A turning pad is provided by assembling a square of rods with enveloping skidding tubes, and adding a diagonal skidding cylinder.

This application is a continuation-in-part of U.S. Pat. application Ser.No. 454,310 filed Dec. 22, 1989, now abandoned.

FIELD OF THE INVENTION

This invention relates to an articulated skidway for a boat wherein theskidway is both collapsible and readily portable. More specifically,this invention relates to an apparatus that is composed of a number ofreadily transportable components that may be assembled on a beach orshoreline to provide a skidway by which a boat may be launched ordrawn-up out of the water.

BACKGROUND TO THE INVENTION

The need to provide lightweight skidways for small craft to permit themto be launched or drawn-up on a shoreline has previously beenrecognized. Examples of prior art patents addressing this objective are:

U.S. Pat. No. 3,579,996--Jerry W. Edson

U.S. Pat. No. 3,587,874--Edwin H. Graf

U.S. Pat. No. 4,803,942--Joseph Dren

U.K. 2,116,123--William G. Watson.

None of these references provide for an articulated slipway, of extendedlength, that is readily portable.

Three patents that do propose structures that provide an articulatedslipway are:

U.S. Pat. No. 4,290,728 to Lucien Leduc

U.S. Pat. No. 2,754,017 to H.E. Hart et al

Italy 480,348 to Giacomo Ghiglione.

In the Leduc patent a series of transverse bars are linked together bychains in a ladder-like manner. These chain-linked bars are supportedbetween longitudinal stringers to provide a support base for planks usedto create a ramp up into the back of a vehicle. However, the chains donot resist collapsing, and it is not readily apparent how this systemcould be deployed on a beach as a non-collapsible skidway.

In the Hart patent a series of racks bearing rollers are deployedprogressively up the side of a beach. The rollers within each rack arerigidly mounted in a rocking frame. The sides of each frame areconsiderably longer than the width of the rollers, and these individualframes are not readily disassemblable. This system is complex and hasaccording, a considerable cost penalty.

The patent to Ghiglione shows a series of transverse slider bars,depicted as being made of wood, held together in an articulatedladder-like array by a series of rods that interconnect joints mountedat the end of each bar or "rung". The specific structure of Ghiglionerelies upon an upper wooden rung upon which the keel of a boat may beslid. This rung is fastened from below to a metal bar that is up-turnedat its outside ends to provide a mount for a pin (4) to which inter-rungconnecting rods are attached. Thus the connections between the rods andrungs in Ghiglione are not articulated in the lateral direction, and theGhiglione skidway can not be swerved sideways in a staggered fashion.Further Ghiglione does not use a tubular skidding cylinder which may berotated to distribute wear.

The articulated detachable structures described are articulated only tobe extent that they are flexible in a single transverse or rotationaldirection. In Leduc the transverse bars are confined laterally by thelongitudinal stringers. In Hart, each rack of rollers may be tippedabout only one axis. And in Ghiglione, the connecting rods are attachedto pins which serve as shafts and limit flexibility to rotation aboutthe axis of such shafts.

None of these references provide a skidway which has the feature ofbeing fully articulated in the sense of being fully articulated, that isto say of being flexible both laterally, in the plane of the skidway,and perpendicularly to the plane of the skidway.

A further need for small boat owners is to provide a turning pad bywhich boats may be re-oriented, once pulled up onto the beach.

Boats are normally landed bow first when landing on a beach. There is aneed for a system by which a boat can be hauled up the track, centeredover a pivoting device and turned around to enable a bow-first launch.This is very advantageous for a number of reasons:

Small outboard powered planing hulls have a weight concentration in thestern often combined with a sharp, squared off transom. They willpotentially "hang up" on a skidway when skidded along stern first. Aturning pad enables boats to be turned 180 degrees and skidded bowfirst.

A bow-first launch is advantageous when launching into wave conditions.

Furthermore the turning pad enables boats to be handled by a singleperson or at least fewer people by enabling them to be skidded bowfirst.

With this background in mind, the invention in its general form willfirst be described, and then its implementation in terms of specificembodiments will be detailed with reference to the drawings followinghereafter. These embodiments are intended to demonstrate the principleof the invention, and the manner of its implementation. The inventionwill then be further described, and defined, in each of the individualclaims which conclude this Specification.

SUMMARY OF THE INVENTION

According to the invention an articulated skidway is provided by aseries of connecting rods, each joined at its respective ends to theends of two other rods by fully articulated detachable coupling means tothereby form an articulated ladder-like formation that is laterallyflexible both in the plane of said formation and perpendicularly to suchplane, there being provided around each rod which serves as a rungwithin such formation, a tubular skidding cylinder.

As a preferred configuration for the invention a series of modularsegments of connecting rods are provided, each module comprising abundle of three rods commonly joined at each of their first ends by anarticulatable coupling and being provided at their respective second,free ends with coupling means by which each of said second ends may bejoined, in an articulated fashion, with the second ends of two otherconnecting rods originating from two other modular segments of rodbundles. The modular segments of connecting rods are capable of beinglaid-out in a ladder-like formation with the rods in each segmentforming a "T" shape wherein the second free end of one rod of eachbundle is connected to the second ends of the rods of two other modularsegments to provide a rung. The skidway is completed by providing on therod which serves as a rung, a tubular skidding cylinder adapted tominimize the resistance to a boat being slid thereover.

Optionally, the skidway may be provided at either or both of its endswith anchor means by which the ends of the skidway may be fastened tothe underlying earth.

By a preferred feature of the invention, the skidding cylinder iscircular in cross-section and is provided with at least twosymmetrically disposed, disc-shaped flanges adapted to maintain a boatgenerally centered on the skidway. Such flanges are preferably mountedinwardly from the ends of the skidding cylinders and may besymmetrically disposed about the centers of the cylinders.

By a further feature of the invention, the rods of each modular segmentsare joined at their first ends by providing one rod with an off-centeredlooped end that forms an off-centered eye, and providing the first endsof the other two rods with looped ends forming eyes that are interlockedwith the off-centered eye so as to permit the three rods to nest insubstantially parallel alignment with each other.

By a further feature of the invention the second, free ends of the rodsin each modular bundle are dimensioned to be joined to the free ends ofrods from other bundles by having a shackle passed through an eye formedby a loop bent into the second ends of each of said rods.

By a further alternate feature of the invention, at least two of saidsecond ends of the rods in each modular segment are provided withsubstantially closed eyes bent therein, and the second end of a thirdrod is provided with a resiliently openable eye formed by terminatingsaid second end of said third rod with a loop that has an extensionportion adapted to permit said resiliently openable eye to beelastically levered open to receive said closed eyes. Optionally saidsubstantially closed eyes may also be resiliently openable.

This invention provides a skidway system that supplied as a "kit" andcan be installed or removed easily and quickly with no specialmechanical aptitude or previous experience. For example a 24 footsection can be installed by the average person in 1/2 hour with noprevious experience. It can be extended to any length. It can beutilized on most surfaces including concrete, rock, cobble stone,gravel, shale, clay, sand, or mud. Constructed of suitable materials itwill withstand corrosive conditions well, as well as wear and tear fromthe elements.

By reason of the compact nature of the individual components, thisproduct is small enough when dismantled and packed so as to be easilystored in a small space e.g. boat locker, car trunk etc. It is lightenough to be easily handled by any average person.

The frictional resistance to propelling a boat or object along the trackis minimal, with the use of skidding cylinders composed of high density,polyethylene plastic tubing. This type of plastic also has the propertyof not being brittle in freezing conditions and is highly resistant todamage by ultra violet rays.

The skidding cylinder is preferably of a larger inside diameter than therods, thus having a "sloppy" fit. This ensures that the skid is free topivot around the rung member of the ladder-like track and ensureslongevity by presenting more wear surface through random or intentionalrotational repositioning of the cylinder.

The use of flanges is incorporated into the skids to provide directionalcontrol and maintain alignment of the object or boat being slid alongthe track. Such flanges are principally located inwardly from the endsof the skidding cylinders. Two pairs of flanges may also be employed ona cylinder, respectively with pairs located both on the outside ends ofthe skidding cylinders and inwardly from the ends, but removed from thecenter.

The invention of using plastic skidding tubes located by ridged rods maybe adapted to provide a "turning pad", allowing boats to be re-orientedonce pulled up onto the beach.

An array of four skidding cylinders may be assembled usingflexibly-linked connecting rods which are assembled into a squarepattern. Each of the four rods which serve as one side the squarecarries an enveloping skidding tube. The rods are flexibly joined attheir ends. Because the rods are incompressible, the tubes are held inan array which can distort into an even-sided trapezoid which willresist collapsing.

A further skidding cylinder is located diagonally within the square,supported buy a further connecting rod or a chain. Chains may be usedbecause the other rods render the square resistant to collapsing.

When a boat's hull is positioned with this array under its weightcenter, minimal effort is required to skid it around 180 degrees. Thefifth cylinder prevents the boat hull from dropping into the centerspace between the side cylinders.

The foregoing summarizes the principal features of the invention. Theinvention may be further understood by the description of the preferredembodiments, in conjunction with the drawings, which now follow.

SUMMARY OF THE FIGURES

FIG. 1 is a plan view of the skidway, as assembled;

FIG. 2 is a depiction of a three rod bundle that forms one modularsegment;

FIG. 3 shows the free ends of three rods joined by a shackle;

FIG. 4 shows an end view of three rod ends, permanently coupled, with askidding cylinder in place over one rod;

FIGS. 5a and 5b show the coupled ends of the rods connected in a mannerthat allows them to be nested when the skidway is disassembled; and

FIG. 6 shows a rod end with a resiliently openable loop provided with anaccess lever arm.

FIG. 7 shows a turning pad assembled using the components of theinvention.

DESCRIPTION OF PREFERRED EMBODIMENTS

In FIG. 1 a series of outer connecting rods 1 define the sides of theskidway 2. At one end chain 3 extends from the connecting rods 1 to ananchor plate 4 which may be buried in the earth.

Transverse rods 5 carry skidding cylinders 6. To guide and center a boaton the skidway, disc-like flanges 7 are formed on the outside ends ofthe cylinders 6, and inwardly from such ends in symmetrical pairs.

In FIG. 2 a basic module of three rods 1,1,5 is shown, deployed in a "T"shaped configuration. These are joined at their intersecting ends byinter-engagement of eyes 9 formed on the rod ends. The free or secondends of each of the rods 1,1,5 are also provided with outer eyes 10 bentinto the free ends of the rods as loops.

In FIG. 3, three closed outer, free eyes 10 are shown connected by astandard shackle 11 having a horseshoe hooped portion 12 and a threadedlocking pin 13.

This is but one optional means for joining the free ends 10 of the rods1,5. Alternate means would include bolts or the resilient looparrangement shown below.

FIG. 4 is an end view of one of the skidding cylinders 6. This cylinder67 has an outer disc-shaped flange 7 integrally fastened to its outersurfaces. The transverse rod or rung 5 passes into the interior core 14of the cylinder 6. This core has an interior cylindrical surface 15 ofconsiderably greater diameter than that of the transverse connecting rod5. Thus, there is a sloppy fit between the rod 5 and cylinder 6. Thisfeature accommodates flexure of the transverse rod 5 and allows thecylinder 6 to have an outside surface of greater area.

In FIG. 5a a loop 16 is bent into one rod 17 in an offset manner. Theends 18 of two other rods 19 are engaged by the offset loop 16. Thisarrangement allows the rods to nest parallel for storage, as shown inFIG. 5b.

FIG. 6 shows an alternate means for forming a removable coupling on theend of a rod. The rod 20 has a loop 21 formed therein that terminates inan extended lever arm 22. The metal of the loop is selected to beelastically resilient. A rod end of this form may be coupled to an eyeor loop on another rod end by simply spreading the lever arm 22 to hookthe eye ends together, and then allowing the resilient loop 21 toclose-up again.

The rods described herein may be made preferably of mild steel. Toresist corrosion, they should be galvanized, or alternately made ofstainless steel. Preferred diameters are 3/16 inches to 3/8 inches, as acompromise between weight and strength. The "rung" spacing mayconveniently be on the order of 32 inches.

Chain for the anchor may be commonly of 1/4 inch size, but ranging 3/16to 1/2 inch. The anchor plate may be about 9 inches square, a size whichallows sufficient earth to be piled on top to render it relativelyimmobile. Either or both ends of the skidway may be anchored.

The skidding cylinder may be composed of standard high densitypolyethylene pipe. This material is intrinsically slippery. As pipe, itwill tend to act as a roller but will be restrained by the ladder-likeformation of rods. If this cylinder is made of low friction material,however, it is not essential that it rotate and no provision is made fora journal or bearing to facilitate rotation.

In FIG. 7 a turning pad 25 is shown composed of four skidding cylinders26 that are linked together by the opposed pair of connecting rods 28that serve as rungs and the opposed pair of outer rods 29 that join suchrungs. The connecting means 30 joining the ends of the rods 28, 29 arearticulated in a manner that would allow the square-like array 27 to beskewed into a trapazoidal form. However, a diagonal link 31, which maybe a rod or chain, joins one pair of opposed corners 32. This diagonallink 31 also carries a diagonally placed skidding cylinder 33.

So assembled, a boat may be pulled onto the turning pad 25 and thenrotated with minimal effort. Like the skidway, the turning pad 25 sodescribed, is dismantlable and readily transportable for re-assembly.

This turning pad 25 may conveniently be formed at the end of a skidwayof the type previously described; or it may be free-standing as aseparate convenient device for turning boats.

The foregoing disclosure therefore shows how an articulated slipway andturning pad of low cost may be formed from lightweight components, thatmay be easily stored and transported, and which will providesatisfactory service for lightweight boats and the like when assembled.The invention in its broadest aspect, and in its more particulardetails, is further described and defined in the claims which nowfollow.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. An articulated skidwayfor boats and the like comprising a series of connecting rods, eachjoined at its respective ends to the ends of two other rods by flexiblecoupling means in a ladder-like formation, there being provided aroundeach rod which serves as a rung within such formation a tubular skiddingcylinder wherein:(1) said cylinder is circular in cross-section and isprovided with at least two encircling flanges respectively disposed onboth sides of the central, midway portion of the length of saidcylinder, inwardly from the ends thereof, at positions whereby saidflanges will serve to maintain a boat generally centered on the skidway;and (2) such cylinder has an interior cylindrical diameter that isconsiderably greater than that of the connecting rod to provide a sloppyfit between the rod and cylinder for rotation there-between without abearing being therein provided, whereby said cylinder may berotationally repositioned to distribute wear over its surface.
 2. Askidway as in claim 1 comprising:(1) a turning pad wherein at least onepair of outer opposed connecting rods joining the rods that serve asrungs and form a square or trapazoidal array are provided with a pair oftubular enveloping skidding cylinders; and (2) a further skiddingcylinder, diagonally positioned between opposed corners formed by thecoupled connecting rods.
 3. A kit for assembling an articulated skidwayfor boats and the like comprising:(1) a series of modular segments ofconnection rods, each of said modular segments comprising a bundle ofthree rods, each of said rods within each of said segments beingcommonly joined at each of their first ends by a first flexible couplingmeans; (2) second coupling means by which the second ends of each ofsaid rods may be joined, in a flexible fashion, with the second ends oftwo other connecting rods originating from two other modular segments ofconnecting rods,said modular segments being connectable to provide aladder-like formation, with the rods in each segment deployed in a "T"shape wherein the second end of one rod of each modular segment isconnected to the second ends of two rods of two other modular segmentsto provide a rung for said ladder-like formation; and tubular skiddingcylinders wherein each of such cylinders: (3) is dimensioned to fit overeach rod which serves as a rung, and provide a surface upon which boatsmay be slid; (4) is circular in cross-section and is provided with atleast two encircling flanges symmetrically disposed on both sides of thecentral, midway portion of the length of said cylinder, inwardly fromthe ends thereof, at positions whereby said flanges will serve tomaintain a boat generally centered on the skidway; and (5) has aninterior cylindrical diameter that is considerably greater than that ofthe connection rod serving as a rung to provide a sloppy fit between therod and cylinder for rotation there-between without a bearing beingprovided therein, whereby said cylinder
 4. A kit as in claim 3 wherein,one of the rods of each said modular segment is provided with anoff-centered looped end, displaced to one side of the longitudinal axisof said rod, forming an off-centered eye, the first ends of the othertwo rods of each modular segment being provided with looped ends formingeyes that are interlocked with the off-centered eye so as to permit thethree rods to nest in substantially parallel alignment with each other.